This was a great plugin by Alakhnor. Until something happened and spammers hacked into his systems and took over the code.
I used Post Thumb Revisited happily for months on a client's site. Then one day the site's navigation menu (which is created by another plugin) disappeared. Weird. So I put it back. Then something else really weird happened. (Funny, it seems I've blocked the details from my memory... sorry to be vague. Guess I just didn't want to remember the craziness.) Then disasters began that caused the site to be totally unusable. I went to pull from my backups (made faithfully by WP Database Backup... or so I thought), and I discovered no backups had been made for months. I was working on it one day and as I was fixing one thing, others were breaking before my very eyes. All seemingly unrelated things. I felt like i was trying to stitch a seam into an antique fabric that was tearing worse and worse as I touched it.
Many hours later I figured out Post Thumb Revised was the cause. The word on the internets was that the plugin has been hacked. I could see malicious code all over my clients installation.
In the end I got everything back. I erased all the files from the server, installed fresh brand new versions of everything (WP core, theme core, all plugins) since the malware robots were breaking other plugins. I copied over the uploads directory, and the files specific to my custom theme. I prayed the database wasn't corrupted, and that everything would just work out, since i couldn't restore an older db version.
It did. Everything turned out fine, after days of repairs.
I replaced this plugin with WP Post Thumbnail.
It works differently, but well. And the good thing about WP Post Thumbnail, is that if you turn it off and delete it (or it breaks or goes crazy), all of the older posts with thumbnails still work and still display the image.
Hopefully, Automattic will delete this plugin from wordpress.org. It really shouldn't be here anymore. Well, unless Alakhnor returns to reclaim the code from the malware hackers, or someone else forks the code and recreates this plugin without the problems.
Until then, stay far far away from this code.